TFT-LCDs (Thin Film Transistor Liquid Crystal Displays), as a kind of flat panel display device, are more and more widely used in high-quality display field due to their advantages such as small size, low power consumption, no radiation, relatively low manufacture cost and so on. Displays with narrow frames are gradually put into market with the development of display technology and increased demands of customers.
A TFT-LCD display panel is formed by cell-assembling of a first substrate and a second substrate. A sealing material is provided, between the first substrate and the second substrate, with a certain wideness along the edge portions of the two substrates. The first substrate is generally aligned with the second substrate on a side outside the sealing material. A certain amount of light emitted from a backlight source, instead of passing a polarizer, will directly irradiate on a region of the first substrate that is not corresponding to a polarizer. In such a case, some light can irradiate on a color filter layer of the second substrate due to refraction at a certain angle. Therefore, a certain amount of light can pass through the polarizer disposed on the second substrate, and furthermore a display device is usually manufactured with a narrow frame, so users can see a bright line if they watch at an angle that is approximately parallel to the screen of the display device, which can even disadvantageously influence the display effect of the display device in a severe case.